Practical Tools
Converters

File Size Converter

Enter any file size value and unit to see the equivalent in bytes, KB, MB, GB, and TB all at once. Uses the binary definition (1 KB = 1,024 bytes) that most operating systems display. Free, no signup.

Enter a value and select a unit to see all equivalents.
No signupRuns in your browserFormula explained belowGeneral information only

How to use this tool

  1. 1Enter a number in the value field.
  2. 2Select the unit from the dropdown: Bytes, KB, MB, GB, or TB.
  3. 3All equivalent values update instantly - read the result in any unit you need.

Formula used

1 KB = 1,024 bytes. 1 MB = 1,024 KB = 1,048,576 bytes. 1 GB = 1,024 MB = 1,073,741,824 bytes. 1 TB = 1,024 GB. This is the binary (IEC) definition used by Windows, macOS, and most operating systems.

Example

How big is 5.3 GB in MB?

Enter 5.3 in GB. Result: 5,427.2 MB (5.3 x 1,024). Useful when a platform shows limits in MB but your file manager shows GB.

How many KB is a 2.4 MB email attachment?

Enter 2.4 in MB. Result: 2,457.6 KB. Most email services have limits in MB (typically 10-25 MB), so convert to confirm your attachment fits.

Common use cases

  • Checking if a 750 MB video file fits within a 1 GB upload limit
  • Converting a file size shown in bytes in code or a log to a human-readable MB or GB value
  • Comparing image file sizes: understanding that a 2.1 MB PNG is 2,150,400 bytes
  • Calculating how many GB of storage you need to hold a folder of files measured in KB and MB

Common mistakes

  • Confusing the binary definition (1 KB = 1,024 bytes, used by operating systems) with the decimal definition (1 KB = 1,000 bytes, used by hard drive manufacturers) - a 500 GB hard drive shows as about 465 GB in Windows for this reason.
  • Assuming MB and MiB are different things in everyday use - in practice, when Windows or macOS shows 'MB', it means the binary MiB (1,048,576 bytes). The formal IEC distinction is rarely used outside technical specifications.
  • Dividing by 1,000 instead of 1,024 when converting manually - bytes to KB is divided by 1,024, not 1,000. Use this converter to avoid the error.

Frequently asked questions

Is 1 KB equal to 1,000 or 1,024 bytes?

This converter uses the binary definition: 1 KB = 1,024 bytes. This is what Windows, macOS, and most operating systems display. Hard drive manufacturers use the decimal definition (1 KB = 1,000 bytes), which is why a '500 GB' hard drive shows as about 465 GB in your OS.

What is the difference between MB and MiB?

Formally, MB (megabyte) means 1,000,000 bytes (decimal) and MiB (mebibyte) means 1,048,576 bytes (binary). In everyday use, when your OS or most software shows 'MB', it almost always means the binary 1,048,576 bytes. This converter uses the binary definition.

Why does my 1 TB hard drive show as 931 GB?

Hard drive manufacturers use decimal: 1 TB = 1,000,000,000,000 bytes. Your operating system uses binary: 1 TB = 1,099,511,627,776 bytes. So 1,000 GB (decimal) equals about 931 GiB (binary). The drive is as large as advertised - it's a units mismatch.

How many MB is 1 GB?

1 GB = 1,024 MB in binary (what your OS shows). 1 GB = 1,000 MB in decimal (what storage manufacturers use). For everyday file management on a computer, use 1,024.

What is the largest unit shown?

TB (terabyte). 1 TB = 1,024 GB. For reference: a typical 4K movie is 50-100 GB, a 1 TB drive holds around 200,000 photos at 5 MB each, and a 1 TB SSD holds around 500 hours of HD video.

Why do some platforms show file sizes in KB and others in MB?

Different platforms, CMSs, and applications display file sizes in different units. Use this converter to quickly translate between them. For example, if a form says 'max 2,048 KB', enter 2,048 in KB and see it equals exactly 2 MB.

Related tools

Last updated